“The Manor,” Mac Griswold’s meticulous scholarly history of an estate and a family, begins with an eerie discovery.

As Griswold is boating around Shelter Island, near the eastern tip of Long Island, she spies “a big yellow house,” of obvious 18th-century origins, surrounded by gigantic boxwoods. A landscape historian, she can’t resist disembarking to explore the site. She finds a land bridge carpeted with grass and grand gardens that converge on a distant gate.

"This place isn't self-consciously 'historic'; it's not restored in any sense," she writes. "This place stands still, outside any ordinary dimension of time or space, but time and tide move through it."

Griswold is clearly transfixed, but her already excellent adventure improves markedly when she secures an invitation to visit from the estate's owners, Alice and Andrew Fiske. Andrew, it turns out, is the 15th member of his family to live there, in an unbroken line, since the early 1650s. The house, itself a historical artifact, is filled with memorabilia, including portraits, antique jewelry and porcelain. In a locked vault, Andrew has secreted a cache of thousands of documents — letters, wills, inventories and more — that would be catnip to any historian.

Over time, Griswold is able to spur archaeological excavation of the site, and to conduct her own research into the estate and its historical context. The result is a pointillist, carefully footnoted account blending past and present — an impressive chronicle that may prove too discursive for all but the most patient and interested readers.

The news hook for "The Manor" is contained in its subtitle — "Three Centuries at a Slave Plantation on Long Island." Like other Northerners, the Sylvester family that settled Shelter Island used slaves as both farm help and domestic servants. The current house, the second on the site, contains a "slave staircase" leading to the attic — a striking architectural feature that the Fiskes (now deceased) apparently took in stride. Both the original 17th-century dwelling and the current one were built by slaves.

The persistence of slavery in the northern United States until at least the early 19th century has come under greater scrutiny in recent years. Beginning in 2005, the New-York Historical Society documented slavery in New York in two well-received exhibitions. Historians of slavery such as Ira Berlin ("Many Thousands Gone: The First Two Centuries of Slavery in North America") also have tackled the subject.

Other writers, including Thomas Norman DeWolf ("Inheriting the Trade: A Northern Family Confronts its Legacy as the Largest Slave-Trading Dynasty in U.S. History") and C.S. Manegold ("Ten Hills Farm: The Forgotten History of Slavery in the North") have added specific portraits of slaveholding Northerners.

Griswold belongs to this second tradition but draws on the insights of Berlin and others. Quoting Berlin, she notes that the relationship between slave and owner, though "imposed and maintained by violence," involved a negotiation in which the slave had some degree of agency. She applies similar insights to her discussion of the Native Americans who were an integral part of the original plantation's cultural mix.

But by far the most extensive section of "The Manor" deals with Nathaniel Sylvester, founding member of the dynasty that populated Shelter Island. Born in Amsterdam to English émigrés, Sylvester (circa 1620-80) joined the family business, becoming a seafaring merchant. The enterprising Griswold tracks him through the archives and streets of Amsterdam to Barbados, where he apparently first encountered slavery.

By 1653, Sylvester and three partners had purchased Shelter Island. It was he who settled there, with his well-connected 17-year-old bride, Grizzell Brinley. Originally Puritans, they became Quakers in the New World, and their island served as a haven for other Quakers fleeing persecution. But like other 17th-century Quaker slaveholders, Griswold writes, "they enjoyed the economic benefits of owning human property while professing their belief in the sacredness of the individual."

The other great character in "The Manor" is Eben Norton Horsford (1818-93), a Harvard chemistry professor, inventor and entrepreneur. He inherited the estate through marriage (first to one sister, then, after her death, to a younger one). The Horsfords used Sylvester Manor as a summer retreat. "The family came to Shelter Island and bathed in the formidable quiet," Griswold writes, but they also entertained the country's leading poets and scientists. It was Horsford who bought out island land owned by Julia Havens, a free black woman whose parents had been slaves, for what Griswold concludes were bargain-basement prices.

Whatever her landscape predilections, Griswold is no fan of the straight line in narrative. She delights in following the manifold byways of her story, indulging in discussions of intra-Protestant religious warfare, the status of 17th-century women, the methods of historical archaeology and other arcana. Not every reader will share her delight. But in the end, it's fair to say that the fascinations of "The Manor" are more or less identical to its failings.

Julia M. Klein is a cultural reporter and critic in Philadelphia and a contributing editor at Columbia Journalism Review.